During certain types of medical surgery or treatment, an introducer is used to access the vascular system of a patient. The introducer is inserted through the wall of a blood vessel in order to obtain access to the vascular system and may thereafter be used for guiding medical instruments such as catheters, guide wires and the like.
After completion of the medical procedure, there will be an incision or a wound in the wall of the blood vessel corresponding to the size of the introducer. The bleeding from the wound, which is a result of such a surgical operation, can be stopped by applying direct pressure on the wound. However, applying direct pressure on the wound will require assistance of medical personnel and may also restrict the flow of blood through the vessel.
In the U.S. Pat. No. 6,508,828, which is assigned to the present assignee, a sealing device is disclosed for sealing a puncture hole in a vessel wall. The sealing device comprises an inner sealing member, an outer member, and a retaining member. The inner sealing member is adapted to be positioned adjacent to the puncture hole on the inside of a vessel, while the outer member is adapted to be positioned adjacent to the opening on the outside of the vessel. To achieve this, the inner member is deployed inside the vessel, thereafter the assembly is retracted so that the inner member is adjacent to the puncture, and subsequently, the outer member is deployed outside the vessel and thereafter tamped down against the vessel puncture. Thus, the inner and outer members sandwich the vessel wall, and are held together by the retaining member to thereby seal the puncture hole in the vessel wall. The retaining member and the outer member are here held in place by friction acting between the retaining member and the outer member.
An improved tamping mechanism is described in U.S. Pat. No. 6,929,655 and European Patent No. EP 1 266 626, which are assigned to the present assignee. Here, the two functional operations of retracting a pusher used to deploy the inner seal in a vessel and subsequently advancing the outer seal with a tamping tube are combined into a single manual operation. In addition, a third step of releasing a thread, which is used to hold the inner and outer seals together, from a holder, can be included in the single manual step.
Other examples of similar devices include those described in U.S. Pat. No. 7,250,057 and U.S. Patent Publication Nos. 2006/0229674 and 2007/0032823, in which a tissue puncture closure device comprises different types of tamping systems, all of which use the motive force applied when retracting the device and subsequently convert this into a tamping force to tamp a sealing plug against the outer side of a vessel puncture. In this procedure the force of tamping originates at the vessel puncture site, thereby exerting strain on the vessel wall. Depending on the amount of force applied, this could potentially rupture the vessel further, leading to an opposite effect of that which is desired, specifically, additional bleeding and further health risks for the patient.